Every time a regulator is hired by a company that they formerly regulated, there should be a full audit looking for any conflicts of interest in their entire time at the regulator. And charges on both sides of the bribery equation if any are found, including both the company itself and any employees, executives, and owners involved or who had knowledge of it and didn't step forward.

And if the company has policies that make it less likely that evidence is found, then go after everyone who was involved in making or approving those policies.